In what is likely to be just one of several steps ultimately leading to the complete dissolution of the Delta-Alaska Airlines frequent-flyer program tie-up, the two feuding airlines have begun chipping away at the reciprocal elite benefits that have been a centerpiece of their longstanding preferred marketing relationship.

For the time being, the following elite perks will remain in place for Mileage Plan elites flying Delta:

Elite bonus miles

Complimentary upgrades "within the United States (excluding Hawaii), Canada, Mexico, and select Caribbean destinations. Not available on nonstop flights between New York (JFK) and Los Angeles, San Francisco, or Seattle"

Neither airline has committed to a timetable for terminating the frequent-flyer relationship completely, but my guess is that the partnership will no longer be in place when Delta's new SkyMiles program takes effect on January 1, 2015.